As schematically illustrated in FIG. 1, in conventional envelope transport and packing system 40, an envelope 4 is transported from a feeder apparatus 42 by an intermediate conveyor 50 to an envelope packing assembly 44. The envelope 4 is then packed with an insert 46 at the envelope packing assembly 44 and exited to an exiting conveyor 48. The exiting conveyor 48 then seals the flap 8 of the packed envelope 4 and transports the envelope 4 out of the system 40.
A typical envelope 4 of the type used in an envelope packing system is illustrated in FIG. 2. The envelope 4 comprises an envelope body 6 and a flap 8. The flap 8 is connected to the envelope body 6 at a connecting edge 10, and the connecting edge 10 of the envelope body 6 defines a crease formed by folding the envelope flap 8 over the envelope body 6. The envelope body 6 comprises an envelope front wall 12 and an envelope back wall 14. The envelope front wall 12 and back wall 14 are connected at three sides but left unconnected at a side adjacent the connecting edge 10 to form an envelope opening 16. The connected side opposite the envelope opening 16 is an envelope bottom 18, and the two other connected sides are envelope sides 20.
As used herein, a flap-closed configuration occurs when the flap 8 of the envelope 4 is folded along the connecting edge 10 and resting over the envelope body 6. In a flap-open configuration, the flap 8 of the envelope 4 is rotated away from the envelope body 6. Because envelopes are typically sold in a flap-closed configuration for packaging and shipping efficiency, many conventional envelope packing systems are configured to accept envelopes in the flap-closed configuration. As part of the packing process, a flap opening means rotates the flap 8 of the envelope 4 from the flap-closed configuration to the flap-open configuration.
One type of flap opening means uses a jet of air directed towards the flap 8 to rotate the flap into the flap-open configuration. The envelope flap 8, although held in the flap-open configuration by the flap opening means, retains a bias to return to the flap-closed configuration due the crease in the envelope running along the connecting edge 10 of the envelope body 6. However, when the envelope is introduced into a conveyor for subsequent processing and after the connecting edge 10 of the envelope body 6 passes between various feeding mechanisms, such as rollers, the crease in the envelope 4 is substantially flattened, which tends to bias the envelope flap 8 towards the flap-open configuration.
Once the envelope 4 has been conveyed to the packing phase of the envelope packing system, controlling the location of the envelope flap 8 is important to prevent the flap from interfering with the packing of the insert into the envelope body. For example, if the insert contacts the envelope flap during packing, the insert may catch on the flap and cause fouling of the system. Current envelope packing systems control the flap by covering the flap with a flap control feature, such as a plate, finger, or guide, during the packing phase. However, mechanical hold-downs interfere with smooth transition of the insert material into the envelope. In addition, the varying nature of envelope styles and sizes results in limited success when applying a mechanical hold-down mechanism.
A problem associated with these types of flap control features, however, is these conventional flap control features can interfere with other portions of the envelope packing system. For example, in a continuous envelope packing system in which the envelope remains moving during the packing phase, conventional flap control features cannot cover the flap at all times for all types of envelope sizes and construction types without interfering with other portions of the envelope packing system. Furthermore, although the crease in the envelope has been substantially flattened, the envelope may still retain a bias to return to the flap-closed configuration, and if this occurs, the flap may prevent a pusher mechanism from packing the insert into the envelope body. Accordingly, a needs exists for a device and method for improved control of a flap on an envelope that minimizes interference with other portions of the envelope packing system.